The Power of Offshore Wind
- Jun 24, 2018 6:21 pm GMT
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An enormous source of renewable energy is simply evaporating into thin air. Offshore wind, off the north Atlantic states, has the potential to deliver four times the electricity consumption of 12 out of the 14 Atlantic states, or more than 4.5 terawatt hours. Put another way, these twelve states could supply all of their electricity needs from offshore wind. In fact, however, there’s only one offshore wind deployment in the United States, a 30-megawatt project operating off the coast of Rhode Island. By contrast, offshore wind is a significant energy source in Europe, which has a total installed offshore wind capacity of more than 12,600 megawatts, generated by 4,100 grid-connected wind turbines in ten countries, with the United Kingdom in the lead, followed by Germany. What are the downsides preventing utilities from taking advantage of offshore? And what are the real advantages of locating wind farms offshore?
Building and maintaining offshore wind capacity is expensive, more expensive today than building similar capacity on land. It’s particularly expensive locating offshore facilities in water deeper than around 200 feet, or about 60 meters. The depths off the east coast tend to be less than 200 feet, but depths off the west coast are greater. Add to this the very expensive production and installation of power cables to get the power back to land combined with the potential for damage to turbines by wave action and very high winds, particularly during hurricanes, and the costs can be daunting.
Less tangible factors are the largely unknown effect of wind farms on marine animals and birds and the negative aesthetic issue of turbines interfering with pristine ocean views, even when turbines are located up to 26 miles offshore, which render them unpopular among local residents, who may also be concerned about negative consequences for tourism and property values. And government policy, on the federal level, is hardly supportive. The president has expressed skepticism about wind, and the Interior Department’s Bureau of Ocean Energy Management, which actively developed leases for offshore wind generation under the Obama administration, has announced only one new lease under the current administration. Furthermore, the Jones Act of 1920 prohibits foreign vessels from transporting merchandise between points in the United States and from points on the North American continent to installations on the Outer Continental Shelf. This could discourage foreign investors.
While the negatives of investing in offshore wind are real, the advantages probably outweigh them, certainly in the long term. Sophisticated turbine technologies and economies of scale, driven largely by the many installations in Europe, are driving costs down. Advances in construction are making locating wind farms in deeper water further offshore, which results in less public concern, and more and more European wind turbine manufacturers are looking to locate research, development and wind turbine production facilities in the United States. That these European companies are interested in developing and participating in offshore wind projects in the United States is a clear sign that the economic prospects are positive.
The European experience is certainly encouraging. The capital costs of offshore wind generation there are falling sharply. In 2016 the cost for a megawatt of electricity was $3.8 million; at the end of 2017 the cost had fallen to $2.2 million, the downward spiral driven largely by the increase in turbine capacity. According to the U.S. Energy Information Administration, the projected cost of electricity per megawatt-hour in the United States in 2022 will be $140 for coal, $110 for natural gas and $157 for offshore wind. Those numbers, however, do not take into account tax credits, which significantly boost wind power’s competitiveness. The offshore wind industry aims to soon produce electricity at a cost equal to, or lower than, coal or natural gas. Add to that the incalculable benefits of clean energy and offshore wind becomes extremely competitive.
Even compared with other green sources, offshore wind has distinct advantages. Just a slight increase in wind speed translates into large increases in energy output. A turbine in a 15-mph wind generates twice as much energy as a turbine in a 12-mph wind. Offshore wind speeds also tend to be steadier than onshore wind, which translates to a more reliable source of energy. And while deployment of offshore wind in the United States has been limited to a single 30-MW project that operates off the coast of Rhode Island, there are a large number of projects in active development. As of February 2018, 13 Atlantic offshore wind projects had leases and were moving forward. Those projects have an estimated 14.2 GW of capacity, enough to power about 5.2 million homes. And the capacity of these proposed projects represents just 1 percent of Atlantic offshore wind’s technical potential. In short, the negatives are real, but diminishing; the positives are enormous and expanding.